ToCharArray converts strings to character arrays. It is called on a string and returns a new char array. You can manipulate this array in-place, which you can't do with a string. This makes many performance optimizations possible.

Example. First we use ToCharArray to receive a character array from the contents of a string. The example uses an input string, and then assigns a char array to the result of the parameterless instance method ToCharArray().

Next: It uses a for-loop to get each character in the array, finally writing it to the Console.

Uses. With ToCharArray, the char array you receive is mutable. This means you can change each individual character. For this reason, the method is ideal when you need to transform characters, as in ROT13, or uppercasing the first letter.

Internals. ToCharArray uses unsafe code that manipulates pointers, along with the private wstrcpyPtrAligned method in the base class library. It is normally faster than doing the same thing in managed code, which has to check array bounds.

However: It makes a complete pass over the string, so if you do not require that, filling character arrays manually may be faster.

Summary. ToCharArray, a method on the string type, is often useful. It returns a character array filled with the string's characters. We can modify this array in-place. This improves the performance of code.

Finally: We looked at practical uses of ToCharArray and its internals in the base class library.